Using a method of retroviral gene transduction we have been able to generate conditionally immortalized long-term hematopoietic stem cell lines from primary mouse bone marrow stem cells. Phase I of this project includes testing the same technology in human cells and the subsequent analysis of those cells in the laboratory and in mice. In addition, the project includes knockdown of HIV-1 co-receptors to generate HIV-1 resistant cells in a mouse model. The method to genetically modify the long-term hematopoietic stem cell lines includes state-of-the-art vector transduction with shRNA containing constructs. Phase II of the project will entail testing this approach in a primate model and optimizing large-scale production of genetically-modified conditionally-immortalized long-term hematopoietic stem cells for testing in clinical trials. [unreadable] [unreadable] This project seeks to refine appropriate methods to genetically manipulate conditionally immortalized hematopoietic stem cell lines to generate HIV-1 resistant cells. Once these methods have been established for the human, the long-term goal to benefit public health will be to use these cells for treating HIV-1 infected patients to re-establish a functional immune system that is protected from endogenous or exogenous sources of HIV. [unreadable] [unreadable] [unreadable]